This card is awesome and unbelievably quiet! I swapped this for my Asus AMD 4890 and there is a massive performance difference at 1920x1080@60Hz (normal HD Television spec). All my games (e.g. Crysis 2, Battle Field 3, Alien Vs Predator) are smooth and run flawlessly on pretty max'd out settings.
However, I would advise if you are considering this card to ensure that your PC case has good air flow. This card has excellent heat dissipation, it is quiet and seems to pump heat out pretty quick, but not all of the air goes out the back. - If your case does have good air flow then this will not be a problem, a case with poor air flow could mean that this excess heat may get sucked into your CPU's fan and cause the CPU's temperature to rise.
Additionally, the 7.1 HDMI sound (transferred via the HDMI cable) is excellent and really allow games to 'come to life'. BIO-Shock 2 and Battle Field 3 are particularly good that this.
[PC Specification: Intel Quad Core @3.6GHz with 8GB Ram]